1. Field of the Invention
The present invention relates to a voltage pumping circuit, and particularly relates to a voltage pumping circuit having voltage pumping paths with different numbers of pumping stages.
2. Description of the Prior Art
Power/Current used generating pumped supplies are the major components of IDD indicating the current one circuit/part consumes. Current efficiency for the pump supplies is very dependent on the number of pumping stages. In order to get higher current efficiency, less number of stages is preferred for pump cores. However, the less number of pumping stages, the lower max output voltage.
Therefore, it is a trade off between current efficiency and output voltage, which is hard to design, if the number of the pumping stages that a voltage pumping circuit can use is fixed.